Sorption of Hg2+, Nd3+, Dy3+, and U
Ions at Polysiloxane Xerogels Functionalized with Phosphonic Acid Derivatives
O. A. Dudarko1, V. P. Goncharik1, V. Ya. Semenii2, and Yu. L. Zub1
1 Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine,
ul. Generala Naumova 17, Kiev, 03164 Ukraine
2 Institute of Organic Chemistry, National Academy of Sciences of Ukraine, ul. Murmanskaya 5, Kiev, 02094 Ukraine
Received June 14, 2007
Abstract — The sorption properties of silicas with mono- and bifunctional surface layers containing the complexing fragment 
Si(CH2)3NHP(S)(OC2H5)2 were studied. It was found that xerogels synthesized by the solgel method (like mesoporous silicas obtained by the template method) can extract mercury(II) ions from acid-ified solutions (SSC up to 450 mg/g). In a nonporous xerogel with a bifunctional surface layer (P=S/
SH), thiol groups proved to be primary sorption sites for Hg2+ ions; part of the ligand groups were inaccessible to metal ions. Xerogels containing the phosphonic acid residues Si(CH2)2P(O)(OH)2 sorbed uranyl and lanthanide ions from their nitrate solutions. The resulting surface complexes contained two (for the U
ion) or three innersphere ligand groups (for the Nd3+ and Dy3+ ions). The maximum SSCs were 340 mg/g for the uranyl ion and 120 mg/g for the lanthanide ions.
Si(CH2)3NHP(S)(OC2H5)2 were studied. It was found that xerogels synthesized by the solgel method (like mesoporous silicas obtained by the template method) can extract mercury(II) ions from acid-ified solutions (SSC up to 450 mg/g). In a nonporous xerogel with a bifunctional surface layer (P=S/SH), thiol groups proved to be primary sorption sites for Hg2+ ions; part of the ligand groups were inaccessible to metal ions. Xerogels containing the phosphonic acid residues Si(CH2)2P(O)(OH)2 sorbed uranyl and lanthanide ions from their nitrate solutions. The resulting surface complexes contained two (for the U ion) or three innersphere ligand groups (for the Nd3+ and Dy3+ ions). The maximum SSCs were 340 mg/g for the uranyl ion and 120 mg/g for the lanthanide ions.
PACS numbers: 68.43.-h
DOI: 10.1134/S003317320802015X